Fusible link or strut



I Jan.

C. F. PECKHAM FUSIBLE LINK 0R STRUT Patented Jan. 4, 1927.

Uhll'lED STATES PATENT @FFECE.

FUSIBLE LINK OR STRUT.

Application filed December 13, 1924. Serial No. 755,788.

My invention relates to fusible links, struts or similar connectionsemployed with automatic fire-extinguishing systems for holding thevalves of sprinkler-heads closed or for retaining fire doors, shuttersor the like normally open, and consists in improvements in theconstruction and method of operation of the same.

One object of the invention 1s to provide a device of the type specifiedin which the separable parts of the link or strut may be more securelybonded or held together by the fusible material, while being adapted forquicker release when exposed to a predetermined degree of heat.

Another object of the invention is to provide a link or strut in whichthe separable members interengage or interlock 111 such manner as totake the stress of the parts which they hold, without placing unduestraln on the fusible material which bonds them together. 4

Another object of the invention is to provide a device of the typespecified 1n which the separable parts of the links have a tendency tospring apart upon the fusing of their bond so that their release will besubstantially instantaneous and posit ve without any chance of stickingor dragging.

Another object of the invention 1s to provide a link or strut of simpleconstructlon adapted for economical manufacture and capable of beingproduced in large quantitles with greater uniformity to insure therequired degree of accuracy 1n its control of the devices which itoperates.

Further objects of the improvement are set forth in the followingspecification wh ch describes a preferred embodiment of the 111- ventionas illustrated by the accompanying drawings. In the drawings Fig. 1 is aperspective view illustrating my improved fusible l1nk or strut appliedto use on a sprinkler-head to connect the arms or levers which holdthevalve closed;

Fig. 2 is an enlarged plan View of the fus1- ble link or strut showingit in its preferred form: n

Fig. 3 is a greatly magnified plan view showing portions of the overlyng strips of wire-netting or screen-cloth which form the two parts ofthe link with their strands interengaging to substantially lock theparts against longitudinal movement;

Fig. 4; is a lateral cross-sectional view taken on line 4-4 of Fig. 8,and also showing the manner in which the strands of the two strips ofscreen-cloth interlock;

F 5 is a similar magnified longitudinal sectional view taken on the line55 of Fig. 3, and further illustrative of the inter'engagement of thestrands of the two strips of screen-cloth; and

Fig. 6 is a plan view of a modified form of the improved fusible link orstrut.

Referring first to Figs. 1 and 2 of the drawings, a preferred form of myimproved link or strut comprises two sections or strips 2 and 3 ofreticulated material, such as wirenetting or screen-cloth, laid one overthe other and bonded together with solder or an equivalent fusible metalwhich is flowed through the interstices of the mesh.

To prevent the strands of the screencloth from pulling apart orravelling at the ends of the strips 2 and 3 I may employ suitablebinding-strips 4 of thin sheet-metal folded over the edges thereof andcrimped thereagainst, or fastened permanently thereto with hard solderor by brazing. Each strip or section 2 and 3 of the link has a hole oreye 5 punched through the netting near its end, and preferably the eyesare formed partly in the binder-strips f after the latter are applied tothe netting so that they serve as a reinforcement for the holes. Asillustrated in Fig. 2, the holes or eyes 5 in the two strips 2 and 8register where the ends of one strip overlies the punched port1on of theother strip, it being noted that one strip preferably .does not extendthe full length of the other strip but is short of the edge of thebinder-strip 4;. It will be understood that the holes or eyes 5 providemeans for engaging the link or strut with the hooked ends of thevalve-levers 1 of the sprinkler-head H, see Fig. 1, or in otherinstances they may receive the hooks at the ends of the wire cords orchains employed for holding lire-doors or shutters. In either case thelevers or other parts to be held to gether will engage against thereinforcing binderstrips at at the ends of the two members 2 and 3 sothat there will be no tendency to pull apart the strands of the nettingor screen-cloth.

Referring now to Figs. 3, 4 and 5, the two strips or sections 2 and 3 ofthe link are superimposed in such manner that the projecting bends orknuckles of the lateral strands of wire on the face of one strip will.

interlock with or engage. against the corre- 5 also illustrates theinterengagement or interlocking of the lateral strands at 70, 7c,

. the purpose of this arrangement being to restrain the two strips fromsliding longitudinally with respect to each other.

After the strips 2 and 3 have been laid one over the other with theirstrands of wire interposed and interlocked in the main ner as abovedescribed, the solder s or other fusible metal or alloy is flowed overthem to bond the strips together. Usually the solder s is applied to thestrips or members 2 and 3 across their full width and throughout thegreater portion of their length, but leaving a narrow space between thesolder and the edges of the binder-strips 4. The solder flows freelythrough the mesh of the strips and efi'ects a continuous and substantialbond between the two members or parts of the link so that the joint ispractically proof against accidental rupture or disintegration.

In Fig. 6 I have illustrated another embodiment of the invention inwhich the hinding-strips at the ends of the members 2 and 3 aredispensed with and eyelets 6 inserted through the screen-cloth toprovide means for connecting the link to the parts which it holds.Various other modifications may be made in the method of constructingand reinforcing the parts of the link without departing from the spiritor scope of the in vention. The method of operation of the device is asfollows:

After the two parts of the link have been placed one over the other andbonded together in the manner as above explained the whole forms arelatively light-weight, yet strong and sturdy connecting device whichmay be used for various purposes as well known to those versed in theart. W'hen employed as a link or strut for sprinklerheads, as shown inFig. 1, the ends of the valve-levers 1 are hooked through the holes 5 atthe ends of the link to hold the ;.valve closed, and the link willsustain a very considerable stress without danger of rupturing thesoldered bond and pulling the two sections apart. The interlockingengagement between the lateral strands or crosswires of the two stripsof netting tends to resist longitudinal displacement. between the partswhile they are held together by the solder and the solder itself formsa-very secure and substantial bond since it penetrates through theinterstices of the mesh of both strips. lVhen however, the link issubjected. to an abnormal degree of heat the head, or in other uses torelease theconnections of the fire-door or shutter.

\Vith the present improved link or strut the rupture of the bond and theseparation of the parts is accelerated and rendered practicallyinstantaneous due to a peculiar coaction of the novel form ofinterlocking means hereinheforc described. Immediately the solder beginsto soften under the effect of the heat there will be tendency for thetwo parts of the link to spring apart due to a cam-action between theinterlocked crosswires of the netting. That is to say, the tensilestrain tending to pull the link-members lengthwise will have the effectof camming the interengaged cross-wires one on another to cause them toride up over each other to force the two members apart to more quicklybreak the soldered bond. In other words, the rupture of the bond isrendered more prompt, without any tendency for the parts of the link tocling and drag on each other. My invention therefore provides a moreeflicient and dependable device for the purpose intended which is morequickly re sponsive to break the connection when the heat reaches aprescribed degree.

The improved link or strut is adapted for economical manufacture and maybe produced in quantity with a high degree of uniformity as regards thebreaking factor, whereby it is rendered more accurate and dependable inits control. At the same time the peculiar construction of the linkprovides for a secure bond between the parts without danger ofaccidental rupture either in use or under rough handling.

Without limiting myself to the precise de tails of construction andarrangement of the device as herein shown and described, I claim:

1. A fusible link or strut comprising reticulated metal strips held inoverlying relation by a bond of fusible material such as solder.

2. A fusible link or strut comprising reticulated metal stri s held inoverlying relation by a bond of fusible material and provided' withmeans for connecting it with the. parts to be held.

3. A fusible link or strut comprising reticulated metal strips held inoverlying relation by a bond of fusible material and provided with eyesat either end adapted to engage the connections of the parts to be held.

t. A fusible link or strut comprising strips of wire screen-cloth heldin overlying relation by a bond of fusible material and provided Withreinforcing elements permanently secured to their ends to prevent theWires of the screen-cloth from pulling apart.

5. A fusible link or strut comprising strips of Wire screen-cloth heldin overlying relation by a bond of fusible material and havingreinforcing strips of sheet-metal folded over their edges andpermanently secured thereto to prevent the strands of the screen-clothfrom pulling apart.

6. A fusible link or strut comprising reticulated metal strips disposedin overlying relation with the mesh of one strip interlock ing with thatof the other strip and bonded together by fusible material such assolder.

7 A fusible link or strut comprising overa lying strips of Wirescreen-cloth disposed with the laterally extending strands of one stripinterengaging With the corresponding strands of the other strip and heldtogether by a bond of fusible material such as solder. 8. In a device ofthe type specified, the combination of superimposed strips of wirescreen-cloth arranged With the bends of the Wire strands on one stripprojecting into the interstices of the other strip to interlock theWires to resist longitudinal displacement of one strip on the other, andfusible material flowed through the mesh of the strips to bond themtogether.

In testimony whereof I aflix my signature.

CHARLES F. PEOKHAM.

